TL/F/12006
74LCX245
Low-Voltage
Bidirectional
Transceiver
with
5V
Tolerant
Inputs
and
Outputs
October 1995
74LCX245
Low-Voltage Bidirectional Transceiver
with 5V Tolerant Inputs and Outputs
General Description
The LCX245 contains eight non-inverting bidirectional buff-
ers with TRI-STATE
É
outputs and is intended for bus orient-
ed applications. The device is designed for low voltage
(3.3V) V
CC
applications with capability of interfacing to a 5V
signal environment. The T/R input determines the direction
of data flow through the device. The OE input disables both
the A and B ports by placing them in a high impedance
state.
The LCX245 is fabricated with an advanced CMOS technol-
ogy to achieve high speed operation while maintaining
CMOS low power dissipation.
Features
Y
5V tolerant inputs and outputs
Y
7.0 ns t
PD
max, 10 mA I
CCQ
max
Y
Power down high impedance inputs and outputs
Y
Supports live insertion/withdrawal
Y
2.0V – 3.6V V
CC
supply operation
Y
g
24 mA output drive
Y
Implements patented Quiet Series
TM
noise/EMI
reduction circuitry
Y
Functionally compatible with the 74 series 245
Y
Latch-up performance exceeds 500 mA
Y
ESD performance:
Human body model
l
2000V
Machine model
l
200V
Logic Symbols
Connection Diagram
TL/F/12006 – 1
IEEE/IEC
TL/F/12006 – 2
Pin Assignment
for SOIC, SSOP and TSSOP
TL/F/12006 – 3
Pin Names
Description
OE
Output Enable Input
T/R
Transmit/Receive Input
A
0
– A
7
Side A Inputs or TRI-STATE Outputs
B
0
– B
7
Side B Inputs or TRI-STATE Outputs
SOIC JEDEC
SOIC EIAJ
SSOP Type II
TSSOP JEDEC
Order Number
74LCX245WM
74LCX245SJ
74LCX245MSA
74LCX245MTC
74LCX245WMX
74LCX245SJX
74LCX245MSAX
74LCX245MTCX
See NS Package Number
M20B
M20D
MSA20
MTC20
TRI-STATE
É
is a registered trademark of National Semiconductor Corporation.
Quiet Series
TM
is a trademark of National Semiconductor Corporation.
C1995 National Semiconductor Corporation
RRD-B30M115/Printed in U. S. A.
Truth Table
Inputs
Outputs
OE
T/R
L
L
Bus B
0
– B
7
Data to Bus A
0
– A
7
L
H
Bus A
0
– A
7
Data to Bus B
0
– B
7
H
X
HIGH Z State on A
0
– A
7
, B
0
– B
7
H
e
High Voltage Level
L
e
Low Voltage Level
X
e
Immaterial
Z
e
High Impedance
Logic Diagram
TL/F/12006 – 4
2
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Symbol
Parameter
Value
Conditions
Units
V
CC
Supply Voltage
b
0.5 to
a
7.0
V
V
I
DC Input Voltage
b
0.5 to
a
7.0
V
V
O
DC Output Voltage
b
0.5 to
a
7.0
Output in TRI-STATE
V
b
0.5 to V
CC
a
0.5
Output in High or Low State (Note 2)
V
I
IK
DC Input Diode Current
b
50
V
I
k
GND
mA
I
OK
DC Output Diode Current
b
50
V
O
k
GND
mA
a
50
V
O
l
V
CC
I
O
DC Output Source/Sink Current
g
50
mA
I
CC
DC Supply Current per Supply Pin
g
100
mA
I
GND
DC Ground Current per Ground Pin
g
100
mA
T
STG
Storage Temperature
b
65 to
a
150
§
C
Note 1:
The Absolute Maximum Ratings are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these
limits. The parametric values defined in the ‘‘Electrical Characteristics’’ table are not guaranteed at the Absolute Maximum Ratings. The ‘‘Recommended Operating
Conditions’’ table will define the conditions for actual device operation.
Note 2:
I
O
Absolute Maximum Rating must be observed.
Recommended Operating Conditions
Symbol
Parameter
Min
Max
Units
V
CC
Supply Voltage
Operating
2.0
3.6
V
Data Retention
1.5
3.6
V
I
Input Voltage
0
5.5
V
V
O
Output Voltage
HIGH or LOW State
0
V
CC
V
TRI-STATE
0
5.5
I
OH
/I
OL
Output Current
V
CC
e
3.0V
b
3.6V
g
24
mA
V
CC
e
2.7V
g
12
T
A
Free-Air Operating Temperature
b
40
85
§
C
D
t/DV
Input Edge Rate, V
IN
e
0.8V – 2.0V, V
CC
e
3.0V
0
10
ns/V
DC Electrical Characteristics
Symbol
Parameter
Conditions
V
CC
T
A
e b
40
§
C to
a
85
§
C
Units
(V)
Min
Max
V
IH
HIGH Level Input Voltage
2.7 – 3.6
2.0
V
V
IL
LOW Level Input Voltage
2.7 – 3.6
0.8
V
V
OH
HIGH Level Output Voltage
I
OH
e b
100 mA
2.7 – 3.6
V
CC
b
0.2
V
I
OH
e b
12 mA
2.7
2.2
V
I
OH
e b
18 mA
3.0
2.4
V
I
OH
e b
24 mA
3.0
2.2
V
V
OL
LOW Level Output Voltage
I
OL
e
100 mA
2.7 – 3.6
0.2
V
I
OL
e
12 mA
2.7
0.4
V
I
OL
e
16 mA
3.0
0.4
V
I
OL
e
24 mA
3.0
0.55
V
I
I
Input Leakage Current
0
s
V
I
s
5.5V
2.7 – 3.6
g
5.0
m
A
I
OZ
TRI-STATE I/O Leakage
0
s
V
O
s
5.5V
2.7 – 3.6
g
5.0
m
A
V
I
e
V
IH
or V
IL
I
OFF
Power-Off Leakage Current
V
I
or V
O
e
5.5V
0
10
m
A
I
CC
Quiescent Supply Current
V
I
e
V
CC
or GND
2.7 – 3.6
10
m
A
3.6V
s
V
I
, V
O
s
5.5V
2.7 – 3.6
g
10
m
A
D
I
CC
Increase in I
CC
per Input
V
IH
e
V
CC
b
0.6V
2.7 – 3.6
500
m
A
3
AC Electrical Characteristics
Symbol
Parameter
T
A
e b
40
§
C to
a
85
§
C
Units
V
CC
e
3.3V
g
0.3V
V
CC
e
2.7V
Min
Max
Min
Max
t
PHL
Propagation Delay
1.5
7.0
1.5
8.0
ns
t
PLH
A
n
to B
n
or B
n
to A
n
1.5
7.0
1.5
8.0
t
PZL
Output Enable Time
1.5
8.5
1.5
9.5
ns
t
PZH
1.5
8.5
1.5
9.5
t
PLZ
Output Disable Time
1.5
7.5
1.5
8.5
ns
t
PHZ
1.5
7.5
1.5
8.5
t
OSHL
,
Output to Output Skew
1.0
ns
t
OSLH
(Note 1)
1.0
Note 1:
Skew is defined as the absolute value of the difference between the actual propagation delay for any two separate outputs of the same device. The
specification applies to any outputs switching in the same direction, either HIGH to LOW (t
OSHL
) or LOW to HIGH (t
OSLH
).
Dynamic Switching Characteristics
Symbol
Parameter
Conditions
V
CC
(V)
T
A
e
25
§
C
Units
Typical
V
OLP
Quiet Output Dynamic Peak V
OL
C
L
e
50 pF, V
IH
e
3.3V, V
IL
e
0V
3.3
0.8
V
V
OLV
Quiet Output Dynamic Valley V
OL
C
L
e
50 pF, V
IH
e
3.3V, V
IL
e
0V
3.3
0.8
V
Capacitance
Symbol
Parameter
Conditions
Typical
Units
C
IN
Input Capacitance
V
CC
e
Open, V
I
e
0V or V
CC
7
pF
C
I/O
Input/Output Capacitance
V
CC
e
3.3V, V
I
e
0V or V
CC
8
pF
C
PD
Power Dissipation Capacitance
V
CC
e
3.3V, V
I
e
0V or V
CC
, F
e
10 MHz
25
pF
74LCX245 Ordering Information
The device number is used to form part of a simplified purchasing code where the package type and temperature range are
defined as follows:
TL/F/12006 – 5
4
Physical Dimensions
inches (millimeters)
20-Lead (0.300
×
Wide) Molded Small Outline Package, JEDEC
Order Number 74LCX245WM or 74LCX245WMX
NS Package Number M20B
5
Physical Dimensions
inches (millimeters) (Continued)
20-Lead (0.300
×
Wide) Molded Small Outline Package, EIAJ
Order Number 74LCX245SJ or 74LCX245SJX
NS Package Number M20D
6
Physical Dimensions
All dimensions are in millimeters (Continued)
20-Lead Molded Shrink Small Outline Package, EIAJ, Type II
Order Number 74LCX245MSA or 74LCX245MSAX
NS Package Number MSA20
7
74LCX245
Low-Voltage
Bidirectional
Transceiver
with
5V
Tolerant
Inputs
and
Outputs
Physical Dimensions
All dimensions are in millimeters (Continued)
20-Lead Thin Shrink Small Outline Package, JEDEC
Order Number 74LCX245MTC or 74LCX245MTCX
NS Package Number MTC20
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL
SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or
2. A critical component is any component of a life
systems which, (a) are intended for surgical implant
support device or system whose failure to perform can
into the body, or (b) support or sustain life, and whose
be reasonably expected to cause the failure of the life
failure to perform, when properly used in accordance
support device or system, or to affect its safety or
with instructions for use provided in the labeling, can
effectiveness.
be reasonably expected to result in a significant injury
to the user.
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